In smaller ponds, (around an acre), if the ponds have established populations of LMB, and not a lot of cover, the GSH population isn't sustainable due to LMB predation. (IHMO)
In larger BOW's, with sufficient suitable habitat for them, they will stay established.
If you look at different websites that describe the GSH, it's diet and life cycle, I'll bet you find more saying that it eats zooplankton, plant/insects than you will find ones say that it eats fish eggs.
